Case Series of Multisystem Inflammatory Syndrome in Adults Associated with SARS-CoV-2 Infection - United Kingdom and United States, March-August 2020

Coronavirus disease 2019-related hepatic transplant pseudoaneurysm

Coronavirus disease 2019-related transplant hepatic pseudoaneurysms have not been reported but can be life-threatening. They can be either solitary or multiple and can grow rapidly within weeks. They should be classified as mycotic and treated on an emergent basis. Both stenting of the vessel and coil embolization can potentially be viable treatment options of coronavirus disease 2019-related pseudoaneurysms.

Multisystemic Inflammation Influences Prognosis in Fulminant Lymphocytic Myocarditis

BACKGROUND

Multisystem inflammatory syndrome (MIS) is a hyperinflammatory shock associated with cardiac dysfunction and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. However, there are no reports on using MIS criteria, such as multisystemic inflammation (MSI) in fulminant myocarditis, without SARS-CoV-2 infection. This study investigated the differences in clinical characteristics and course between patients with fulminant lymphocytic myocarditis (FLM) plus MSI and those without MSI.Methods and Results: This multicenter retrospective cohort study included 273 patients with FLM registered in the JROAD-DPC database between April 2014 and March 2017. We evaluated the presence of MSI using criteria modified from previously reported MIS criteria and compared the characteristics and risk of mortality or heart transplantation between FLM patients with MSI and without MSI. Of the 273 patients with FLM, 107 (39%) were diagnosed with MSI. The MSI group was younger (44 vs. 57 years; P<0.0001) and had more females (50% vs. 36%; P=0.0236), a higher incidence of pericardial effusion (58% vs. 40%; P=0.0073), and a lower 90-day mortality rate (19% vs. 33%; P=0.0185) than the non-MSI group. The risk of mortality at 90 days was lower in FLM patients aged <50 years with MSI aged <50 years than in those without MSI (P=0.0463).

CONCLUSIONS

These results suggest that MSI may influence the prognosis of FLM, especially in patients aged <50 years.

High Cardiac Troponin Levels in Infants with Acute SARS-CoV-2 Infection: A Prospective Comparative Study

OBJECTIVE

To investigate the specific role of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in inducing elevation of marker of myocardial injury in infants with acute coronavirus disease 2019 (COVID-19).

STUDY DESIGN

A prospective, multicentric 3-arm comparative study (March 2020 through March 2022) enrolling 152 infants hospitalized for COVID-19, 79 children with acute infections other than SARS-CoV-2, and 71 healthy controls. Determination of high-sensitivity cardiac troponin (hs-cTn) levels was the primary outcome.

RESULTS

The proportion of children with hs-cTn values above the upper limit of normal (44 [28.9%]), as well as with a 3-fold increased value (20 [13.2%]) were significantly higher in the COVID-19 group than those in both control groups. The risk of presenting a 3-fold increased hs-cTn value was higher in children with SARS-CoV-2 infection compared with either healthy children (OR, 5.23; 95% CI, 1.19-23.02) or those with other infections (OR, 11.89; 95% CI, 1.56-89.79). In children with COVID-19, hs-cTn elevation was associated with neither clinical nor biochemical characteristics, nor perinatal risk factors, but with an age of <3 months (P < .001). After adjustment for age, sex, and underlying clinical conditions, elevated hs-cTn was independently associated with COVID-19 in a multivariable regression model. All children showed a progressive reduction of hs-cTn until normalization over time, without clinical, ECG, or echocardiographic manifestations up to 1 year of follow-up.

CONCLUSIONS

Infants with acute SARS-CoV-2 infection may show a subclinical and transient alteration of myocardial injury markers, especially in the first months of life. hs-cTn levels normalized during follow-up and were not associated with cardiac functional impairment; nevertheless, long-term consequences are unknown and should be followed carefully.

Cardiac Involvement in Patients With Multisystem Inflammatory Syndrome in Adults

Multisystemic inflammatory syndrome in adults is a hyperinflammatory condition following (within 4-12 weeks) SARS-CoV-2 infection. Here, the dysregulation of the immune system leads to a multiorgan involvement often affecting the heart. Cardiac involvement in multisystemic inflammatory syndrome in adults has been described mainly in young men without other comorbidities and may present with different clinical scenarios, including acute heart failure, life-threatening arrhythmias, pericarditis, and myocarditis, with a nonnegligible risk of mortality (up to 7% of all cases). The heterogeneity of its clinical features and the absence of a clear case definition make the differential diagnosis with other postinfectious (eg, infective myocarditis) and hyperinflammatory diseases (eg, adult Still disease and macrophage activation syndrome) challenging. Moreover, the evidence on the efficacy of specific treatments targeting the hyperinflammatory response underlying this clinical condition (eg, glucocorticoids, immunoglobulins, and other immunomodulatory agents) is sparse and not supported by randomized clinical trials. In this review article, we aim to provide an overview of the clinical features and the diagnostic workup of multisystemic inflammatory syndrome in adults with cardiac involvement, highlighting the possible pathogenetic mechanisms and the therapeutic management, along with remaining knowledge gaps in this field.

Replication and Injury Associated With SARS-CoV-2 in Cultured Hepatocytes

Background

Liver dysfunction is one of the hallmarks of SARS-CoV-2 infection. The mechanism(s) of hepatic injury in SARS-CoV-2 infection remains controversial with some reporting viral replication and cellular injury and others suggesting lack of replication and injury due to non-cytopathogenic etiologies. To investigate this further, we evaluated SARS-CoV-2 replication in immortalized hepatic cell lines and primary hepatocytes, examined whether cell injury was associated with apoptotic pathways, and also determined the effect of the antiviral remdesivir on these processes.

Methods

Immortalized hepatocyte cell lines (HepG2 and Huh7.5), as well as primary human hepatocytes, were exposed to SARS-CoV-2 at a multiplicity of infection of 0.1 PFU/mL. Viral replication was evaluated by plaque assays, immunohistochemical staining for the viral spike protein, and caspase-3 expression evaluated with and without exposure to remdesivir.

Results

All hepatocyte cell lines and primary hepatocytes supported active replication of SARS-CoV-2. Significant cytopathic effect was observed by light microscopy, and caspase-3 staining supported activation of apoptotic pathways. Remdesivir abrogated infection in a dose-dependent fashion and was not independently associated with hepatocyte injury.

Conclusion

Hepatocytes appear to be highly permissive of SARS-CoV-2 replication which leads to rapid cell death associated with activation of apoptotic pathways. Viral replication and hepatocytes injury are abrogated with remdesivir. We conclude that active viral replication is most likely a key contributor to liver enzyme abnormalities observed in the setting of acute SARS-CoV-2 infection.

New insight into the intravenous immunoglobulin treatment in Multisystem Inflammatory Syndrome in children and adults

Within 6 months of the coronavirus pandemic, a new disease entity associated with a multisystem hyperinflammation syndrome as a result of a previous infection with the SARS-CoV-2 virus is increasingly being identified in children termed Multisystem Inflammatory Syndrome in Children (MIS-C) and more recently in adults(MIS-A). Due to its clinical similarity with Kawasaki Disease, some institutions have used intravenous immunoglobulins and steroids as first line agents in the management of the disease. We seek to find how effective intravenous immunoglobulin therapy is across these two disease entities. A comprehensive English literature search was conducted across PubMed, MEDLINE, and EMBASE databases using the keywords multisystem inflammatory syndrome in children/adults and treatment. All major online libraries concerning the diagnosis and treatment of MIS-C and MIS-A were searched. Relevant papers were read, reviewed, and analyzed. The use of intravenous immunoglobulins (IVIG) and steroids for the treatment of multisystemic inflammatory syndrome in children(MIS-C) is well established and recommended by multiple pediatric governing institutions. However, there is still no optimal treatment guideline or consensus on the use of IVIG in adults. The use of IVIG in both the child and adult populations may lower the risk of treatment failure and the need for adjunctive immunomodulatory therapy. Despite the promising results of IVIG use for the management of MIS-C and MIS-A, considering the pathophysiological differences between MIS-C and MIS-A, healthcare professionals need to further assess the differences in disease risk and treatment. The optimal dose, frequency, and duration of treatment are still unknown, more research is needed to establish treatment guidelines.

Coronavirus Receptor Expression Profiles in Human Mast Cells, Basophils, and Eosinophils

A major problem in SARS-CoV-2-infected patients is the massive tissue inflammation in certain target organs, including the lungs. Mast cells (MC), basophils (BA), and eosinophils (EO) are key effector cells in inflammatory processes. These cells have recently been implicated in the pathogenesis of SARS-CoV-2 infections. We explored coronavirus receptor (CoV-R) expression profiles in primary human MC, BA, and EO, and in related cell lines (HMC-1, ROSA, MCPV-1, KU812, and EOL-1). As determined using flow cytometry, primary MC, BA, and EO, and their corresponding cell lines, displayed the CoV-R CD13 and CD147. Primary skin MC and BA, as well as EOL-1 cells, also displayed CD26, whereas primary EO and the MC and BA cell lines failed to express CD26. As assessed using qPCR, most cell lines expressed transcripts for CD13, CD147, and ABL2, whereas ACE2 mRNA was not detectable, and CD26 mRNA was only identified in EOL-1 cells. We also screened for drug effects on CoV-R expression. However, dexamethasone, vitamin D, and hydroxychloroquine did not exert substantial effects on the expression of CD13, CD26, or CD147 in the cells. Together, MC, BA, and EO express distinct CoV-R profiles. Whether these receptors mediate virus-cell interactions and thereby virus-induced inflammation remains unknown at present.

Younger age is associated with cardiovascular pathological phenotype of severe COVID-19 at autopsy

Introduction

COVID-19 affects patients of all ages. There are few autopsy studies focusing on the younger population. We assessed an autopsy cohort aiming to understand how age influences pathological outcomes in fatal COVID-19.

Methods

This study included autopsied patients, aged 6 months to 83 years, with confirmed COVID-19 in 2020-2021. We collected tissue samples from deceased patients using a minimally invasive autopsy protocol and assessed pathological data following a systematic approach.

Results

Eighty-six patients were included, with a median age of 55 years (IQR 32.3-66.0). We showed that age was significantly lower in patients with acute heart ischemia (p = 0.004), myocarditis (p = 0.03) and lung angiomatosis (p < 0.001), and significantly higher in patients with exudative diffuse alveolar damage (p = 0.02), proliferative diffuse alveolar damage (p < 0.001), lung squamous metaplasia (p = 0.003) and lung viral atypia (p = 0.03), compared to patients without those findings. We stratified patients by their age and showed that cardiovascular findings were more prevalent in children and young adults. We performed principal component analysis and cluster of pathological variables, and showed that cardiovascular variables clustered and covariated together, and separated from pulmonary variables.

Conclusion

We showed that age modulates pathological outcomes in fatal COVID-19. Younger age is associated with cardiovascular abnormalities and older age with pulmonary findings.

Blood-derived product therapies for SARS-CoV-2 infection and long COVID

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is capable of large-scale transmission and has caused the coronavirus disease 2019 (COVID-19) pandemic. Patients with COVID-19 may experience persistent long-term health issues, known as long COVID. Both acute SARS-CoV-2 infection and long COVID have resulted in persistent negative impacts on global public health. The effective application and development of blood-derived products are important strategies to combat the serious damage caused by COVID-19. Since the emergence of COVID-19, various blood-derived products that target or do not target SARS-CoV-2 have been investigated for therapeutic applications. SARS-CoV-2-targeting blood-derived products, including COVID-19 convalescent plasma, COVID-19 hyperimmune globulin, and recombinant anti-SARS-CoV-2 neutralizing immunoglobulin G, are virus-targeting and can provide immediate control of viral infection in the short term. Non-SARS-CoV-2-targeting blood-derived products, including intravenous immunoglobulin and human serum albumin exhibit anti-inflammatory, immunomodulatory, antioxidant, and anticoagulatory properties. Rational use of these products can be beneficial to patients with SARS-CoV-2 infection or long COVID. With evidence accumulated since the pandemic began, we here summarize the progress of blood-derived product therapies for COVID-19, discuss the effective methods and scenarios regarding these therapies, and provide guidance and suggestions for clinical treatment.

Multisystem inflammatory syndrome in adults with cardiac engagement: a case report and literature review

Background

Following infection with severe acute respiratory syndrome coronavirus, a post-infectious multisystem inflammatory syndrome in adults (MIS-A) has been identified. It affects multiple organ systems and can lead to multi-organic failure.

Case summary

This case report describes a patient with MIS-A with significant cardiac involvement including peri-myocarditis, pulmonary hypertension, right-sided heart failure, tricuspid regurgitation, and cardiogenic shock. After being diagnosed and treated correctly for MIS-A, the patient recovered completely, without any cardiac sequelae.

Discussion

The hyperinflammation in MIS-A can have cardiac engagement. Although more research is required to further clarify the underlying mechanisms, prompt diagnosis and anti-inflammatory treatment are crucial for better outcomes and cardiac recovery.

Acute perimyocarditis associated with Bartonella henselae infection

Perimyocarditis involves inflammation of the heart muscle and surrounding tissue, causing reduced left ventricular ejection fraction. Typically viral, but occasionally bacterial, this condition can arise from Bartonella henselae, a rare yet potentially serious pathogen that can lead to cardiac inflammation and subsequent heart failure. Since this bacterium is mainly associated with cat scratch disease-which is self-limiting and has a mild disease course-B. henselae's potential role in cardiac disease is underestimated. We present a mid-30s man, immunocompetent, who presented to the emergency department with acute heart failure due to B. henselae-associated perimyocarditis. Despite not recalling any scratches or bites from cats, the patient had been living with cats, which likely exposed him. This case highlights the varied clinical presentations of B. henselae-associated heart disease and underscores the importance of considering this pathogen as a potential cause of perimyocarditis, particularly in individuals with exposure to cats.

Multisystem Inflammatory Syndrome (MIS) following SARS-CoV-2 vaccinations; a systematic review

BACKGROUND

Although SARS-CoV-2 vaccines are generally safe, there are growing concerns about their link to a potentially life-threatening multi-system inflammatory syndrome following vaccination (MIS-V). We conducted this systematic review to elucidate the prevalence of MIS, severity, treatment, and outcomes following SARS-CoV-2 vaccination.

METHODS

We searched PubMed, Scopus, ScienceDirect, Google Scholar, Virtual Health Library (VHL), Cochrane Library, and Web of Science databases for articles and case reports about MIS-V. We performed a qualitative analysis of individual cases from the included studies.

RESULTS

Of the 1366 studies identified by database search, we retrieved twenty-six case reports and two cohort studies. We analyzed the data of 37 individual cases extracted from 27 articles. The average age of the cases included in this review was 18 (1-67) years, with the most being male (M: F 3.1:1). Of the 37 included cases, the cardiovascular system was the most affected system by MIS (36, 97.3%), followed by the gastrointestinal tract (32, 86.5%).

CONCLUSION

MIS after SARS-CoV-2 vaccinations can be fatal, but the incidence is low. Prompt recognition of MIS and ruling out the mimickers are critical in the patient's early recovery.

Multisystem inflammatory syndrome in systemic lupus erythematosus patient with COVID-19: Case report and review

Multisystem inflammatory syndrome in adults (MIS-A) is considered a rare and serious complication of coronavirus disease 2019, which more frequently occurs in young, male, and either non-Hispanic black or Hispanic persons. Here we present a Chinese woman aged 50 years with systemic lupus erythematosus diagnosed with MIS-A. She experienced unexpected sudden cardiac and liver injuries and hemodynamic collapse, and her platelet count dropped sharply on hospital day 2. Unfortunately, the patient's condition gradually deteriorated despite maximum support and she died on day 3. We present this rare case to emphasize that MIS-A in autoimmune diseases may be more severe and its management may be more difficult.

Treatments and Severe Outcomes for Patients Diagnosed With MIS-C at Four Children's Hospitals in the United States, March 16, 2020-March 10, 2021

BACKGROUND

Clinical management of multisystem inflammatory syndrome in children (MIS-C) has varied over time and by medical institution.

METHODS

Data on patients with MIS-C were collected from 4 children's hospitals between March 16, 2020 and March 10, 2021. Relationships between MIS-C treatments and patient demographics, clinical characteristics, and outcomes were described. Propensity score matching was utilized to assess the relative risk of outcomes dependent on early treatment with intravenous immunoglobulin (IVIG) or low-dose steroids, controlling for potential confounding variables.

RESULTS

Of 233 patients diagnosed with MIS-C, the most commonly administered treatments were steroids (88.4%), aspirin (81.1%), IVIG (77.7%) and anticoagulants (71.2%). Compared with those patients without respiratory features, patients with respiratory features were less likely to receive IVIG and steroids on the same day (combination treatment) (44.1%). Controlling for confounding variables, patients receiving IVIG within 1 day of hospitalization were less likely to have hospital length of stay ≥8 days (RR = 0.53, 95% CI: 0.31-0.88). Patients receiving low-dose steroids within 1 day of hospitalization were less likely to develop ventricular dysfunction (RR = 0.45, 95% CI: 0.26-0.77), have increasingly elevated troponin levels (RR = 0.55, 95% CI: 0.40-0.75) or have hospital length of stay ≥8 days (RR = 0.46, 95% CI: 0.29-0.74).

CONCLUSION

Treatments for MIS-C differed by hospital, patient characteristics and illness severity. When IVIG and low-dose steroids were administered in combination or low-dose steroids were administered alone within 1 day of hospitalization, the risk of subsequent severe outcomes was decreased.

COVID-19-related multisystem inflammatory syndrome in adult: the first death in Brazil

The precise pathogenesis of COVID-19-related multisystem inflammatory syndrome remains largely elusive, despite its rarity. The syndrome symptoms often overlap with those of other infections, posing challenges for prompt diagnosis. A male patient, 34 years old, was admitted with suspicion of severe dengue, rapidly progressing to multiple organ dysfunction. Dengue tests resulted negative, and he passed away after four days. This case occurred approximately four weeks after the initial onset of COVID-19 and met all diagnostic criteria as defined by the Centers for Disease Control and Prevention. This report presents the first documented case of fatal multisystem inflammatory syndrome in adult (MIS-A) in Brazil. Recognizing the significance of suspecting this syndrome and promptly initiating treatment at an early stage are essential for minimizing damage and mortality.

Delayed inflammatory pulmonary syndrome: A distinct clinical entity in the spectrum of inflammatory syndromes in COVID-19 infection?

BACKGROUND

During the second wave of the coronavirus disease 2019 (COVID-19) pandemic, a subset of critically ill patients developed delayed respiratory deterioration in the absence of new infection, fluid overload or extra-pulmonary organ dysfunction.

AIM

To describe the clinical and laboratory characteristics, outcomes, and management of these patients, and to contrast this entity with other post COVID-19 immune dysregulation related inflammatory disorders.

METHODS

This was a retrospective observational study of adult patients admitted to the medical intensive care unit of a 2200-bed university affiliated teaching hospital, between May and August 2021, who fulfilled clearly defined inclusion and exclusion criteria. Outcome was assessed by a change in PaO2/FiO2 ratio and levels of inflammatory markers before and after immunomodulation, duration of mechanical ventilation after starting treatment, and survival to discharge.

RESULTS

Five patients developed delayed respiratory deterioration in the absence of new infection, fluid overload or extra-pulmonary organ dysfunction at a median interquartile range (IQR) duration of 32 (23-35) d after the onset of symptoms. These patients had elevated inflammatory markers, required mechanical ventilation for 13 (IQR 10-23) d, and responded to glucocorticoids and/or intravenous immunoglobulin. One patient died (20%).

CONCLUSION

This delayed respiratory worsening with elevated inflammatory markers and clinical response to immunomodulation appears to contrast the well described Multisystem Inflammatory Syndrome - Adults by the paucity of extrapulmonary organ involvement. The diagnosis can be considered in patients presenting with delayed respiratory worsening, that is not attributable to cardiac dysfunction, fluid overload or ongoing infections, and associated with an increase in systemic inflammatory markers like C-reactive protein, inteleukin-6 and ferritin. A good response to immunomodulation can be expected. This delayed inflammatory pulmonary syndrome may represent a distinct clinical entity in the spectrum of inflammatory syndromes in COVID-19 infection.

Severe systemic inflammation mimicking TAFRO syndrome following COVID-19

TAFRO syndrome is a rare systemic inflammatory disease. Its pathogenesis mainly involves excessive cytokine secretion and autoimmune dysfunction. Although its etiology is unclear, some viral infections have been reported to cause it. Here, we report a case of severe systemic inflammation mimicking TAFRO syndrome that arose after COVID-19. A 61-years-old woman suffered from a continuous fever, ascites, and edema after contracting COVID-19. She developed progressive thrombocytopenia, renal failure, and elevated C-reactive protein levels. She was tentatively diagnosed with multisystem inflammatory syndrome in adults (MIS-A) and received steroid pulse therapy. However, she exhibited worsening fluid retention and progressive renal failure, which are not typical of MIS-A. A bone marrow examination showed reticulin myelofibrosis and an increased number of megakaryocytes. Although a definitive diagnosis of TAFRO syndrome was not made according to current diagnostic criteria, we determined that her symptoms were clinically consistent with those of TAFRO syndrome. Combination therapy, including steroid pulse therapy, plasma exchange, rituximab, and cyclosporine, improved her symptoms. There are pathological similarities between hyperinflammation that arises after COVID-19 and TAFRO syndrome in terms of the associated cytokine storms. COVID-19 may have triggered the development of systemic inflammation mimicking TAFRO syndrome in this case.

Multisystem Inflammatory Syndrome in an Adult on Hemodialysis with Markedly Elevated Procalcitonin and Ferritin Levels

A 21-year-old man on hemodialysis was hospitalized for coronavirus disease 2019 (COVID-19) pneumonia. After admission, he had a persistent high fever and developed erythema induratum on his extremities. Laboratory tests conducted 25 days after onset showed markedly increased procalcitonin (PCT) levels (>100 ng/mL). The patient developed impaired consciousness and hypotensive shock and required endotracheal intubation. Based on the presence of erythema induratum and multiorgan dysfunction, he was diagnosed with multisystem inflammatory syndrome (MIS). The MIS resolved after treatment with intravenous immunoglobulin and methylprednisolone. This report illustrates that MIS can occur in adults and may be accompanied by high PCT levels.

A global systematic review and meta-analysis on the emerging evidence on risk factors, clinical characteristics, and prognosis of multisystem inflammatory syndrome in adults (MIS-A)

Background

The multisystem inflammatory syndrome in adults (MIS-A) has emerged, similar to those in children associated with SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) [multisystem inflammatory syndrome in children (MIS-C)]. This review aimed to analyze the risk factors, clinical course, and prognosis of MIS-A.

Methods

A comprehensive literature search was conducted using several databases for cases reporting MIS-A from 1 December 2019 till 9 September 2021. The case definitions used to identify potential cases were those recommended by the World Health Organization, Center for Disease Control, and individual country/physician classification. The meta-analysis was performed using Comprehensive Meta-Analysis (CMA) 2.2.027 and Review Manager (RevMan) 5.4.1, employing 95% confidence intervals (CI).

Results

Seventy studies were assessed for full-text eligibility, out of which 37 were included. The mean age of the study population was 32.52±10.29 years. The most common symptoms were fever (89.8%, 95% CI: 77.7-95.7%) and diarrhea (49%, 95% CI: 35.4-62.7%). Ventricular tachycardia (57.1%, 95% CI: 43.1-70.1%) was the most common electro-cardiac abnormality. The most common inflammatory marker was elevated C-reactive protein (89.8%, 95% CI: 77.7-95.7%). Abnormal echocardiogram was the most common imaging test result (commonly, ventricular dysfunction and arrhythmias), while steroids were the most administered treatment. Severe cases had a higher need for vasopressor and inotropic support and antibiotic therapy compared to the non-severe cases. One death was reported due to cardiovascular failure.

Conclusion

Our collated findings will help clinicians identify the typical presenting symptoms and optimal management of MIS-A. Further research is required to understand the long-term prognosis and the correlation between coronavirus disease 2019 (COVID-19) and MIS-A to understand its pathogenesis and clinical spectrum.

Clinical significance of serum cytokine profiles for differentiating between Kawasaki disease and its mimickers

OBJECTIVES

To investigate the clinical significance of serum cytokine profiles for differentiating between Kawasaki disease (KD) and its mimickers.

METHODS

Patients with KD, including complete KD, KD shock syndrome (KDSS), and KD with macrophage activation syndrome (KD-MAS), and its mimickers, including multisystem inflammatory syndrome in children, toxic shock syndrome, and Yersinia pseudotuberculosis infection, were enrolled. Serum levels of interleukin (IL)-6, soluble tumor necrosis factor receptor type II (sTNF-RII), IL-10, IL-18, and chemokine (C-X-C motif) ligand 9 (CXCL9) were measured using enzyme-linked immunosorbent assay and compared them with clinical manifestations.

RESULTS

Serum IL-6, sTNF-RII, and IL-10 levels were significantly elevated in patients with KDSS. Serum IL-18 levels were substantially elevated in patients with KD-MAS. Patients with KD-MAS and KD mimickers had significantly elevated serum CXCL9 levels compared with those with complete KD. Area under the receiver operating characteristic curve analysis showed that serum IL-6 was the most useful for differentiating KDSS from the others, IL-18 and CXCL9 for KD-MAS from complete KD, and CXCL9 for KD mimickers from complete KD and KD-MAS.

CONCLUSION

Serum cytokine profiles may be useful for differentiating between KD and its mimickers.

Immune responses to SARS-CoV-2 infection and vaccination in children

During the three years since SARS-CoV-2 infections were first described a wealth of information has been gathered about viral variants and their changing properties, the disease presentations they elicit and how the many vaccines developed in record time protect from COVID-19 severe disease in different populations. A general theme throughout the pandemic has been the observation that children and young people in general fare well, with mild symptoms during acute infection and full recovery thereafter. It has also become clear that this is not universally true, as some children develop severe COVID-19 hypoxic pneumonia and even succumb to the infection, while another group of children develop a rare but serious multisystem inflammatory syndrome (MIS-C) and some other children experience prolonged illness following acute infection, post-COVID. Here I will discuss some of the findings made to explain these diverse disease manifestations in children and young people infected by SARS-CoV-2. I will also discuss the vaccines developed at record speed and their efficacy in protecting children from disease.

Adult-onset Still's disease and fever of unknown origin in India

Despite an essential differential diagnosis for fever of unknown origin (FUO) in young adults, adult-onset Still's disease (AOSD) is infrequently considered and remained underdiagnosed in low-middle-income countries. The present study analyzed the clinical, serological, radiological, and pathological characteristics of AOSD presented as FUO in India. A hospital-based retrospective study of patients aged > 13 years admitted with FUO and later diagnosed with AOSD in Postgraduate Institute of Medical Education and Research, Chandigarh (India), was conducted between January 2014 and December 2020. Petersdorf and Beeson's criteria were used to define FUO. The diagnosis of AOSD was made based on Yamaguchi's criteria. Twenty-seven patients (median age 26 years, 14 females) were enrolled. All presented with intermittent fever with a median duration of 10 weeks. The typical features of AOSD at admission were arthralgia (n = 24), hepatosplenomegaly (n = 21), spiking fever ≥ 39 °C (n = 19), lymphadenopathy (n = 18), typical rash (n = 17), and sore throat (n = 11). Leukocytosis (n = 25) and neutrophilia (n = 19) were frequent. Hyperferritinemia was universal (range, 700-145,003 ng/ml; ≥ 2000, n = 23). At admission, AOSD was suspected in only nine FUO cases, while tuberculosis (n = 16), undifferentiated connective tissue disorder (n = 14), and lymphoproliferative disorder (n = 11) were common diagnostic possibilities. Crispin et al. clinical scale detected AOSD in only 15 (55.5%) FUO patients. Whole-body imaging (n = 27), including fluorodeoxyglucose positron emission tomography (n = 12), demonstrated reticuloendothelial organ-system involvement and serositis. Seventeen (63%) patients had macrophage activation syndrome at the time of AOSD diagnosis. AOSD FUO presents with typical but nonspecific features; thus, early differentiation from common causes (e.g., tuberculosis, lymphoma) is difficult. Macrophage activation syndrome is common in AOSD with FUO presentation.

Epigenetic memory of coronavirus infection in innate immune cells and their progenitors

Inflammation can trigger lasting phenotypes in immune and non-immune cells. Whether and how human infections and associated inflammation can form innate immune memory in hematopoietic stem and progenitor cells (HSPC) has remained unclear. We found that circulating HSPC, enriched from peripheral blood, captured the diversity of bone marrow HSPC, enabling investigation of their epigenomic reprogramming following coronavirus disease 2019 (COVID-19). Alterations in innate immune phenotypes and epigenetic programs of HSPC persisted for months to 1 year following severe COVID-19 and were associated with distinct transcription factor (TF) activities, altered regulation of inflammatory programs, and durable increases in myelopoiesis. HSPC epigenomic alterations were conveyed, through differentiation, to progeny innate immune cells. Early activity of IL-6 contributed to these persistent phenotypes in human COVID-19 and a mouse coronavirus infection model. Epigenetic reprogramming of HSPC may underlie altered immune function following infection and be broadly relevant, especially for millions of COVID-19 survivors.

The Management of COVID-19-Related Coagulopathy: A Focus on the Challenges of Metabolic and Vascular Diseases

The course of COVID-19 is highly dependent on the associated cardiometabolic comorbidities of the patient, which worsen the prognosis of coronavirus infection, mainly due to systemic inflammation, endothelium dysfunction, and thrombosis. A search on the recent medical literature was performed in five languages, using the PubMed, Embase, Cochrane, and Google Scholar databases, for the review of data regarding the management of patients with a high risk for severe COVID-19, focusing on the associated coagulopathy. Special features of COVID-19 management are presented, based on the underlying conditions (obesity, diabetes mellitus, and cardiovascular diseases), emphasizing the necessity of a modern, holistic approach to thromboembolic states. The latest findings regarding the most efficient therapeutic approaches are included in the article, offering guidance for medical professionals in severe, complicated cases of SARS-CoV-2 infection. We can conclude that severe COVID-19 is closely related to vascular inflammation and intense cytokine release leading to hemostasis disorders. Overweight, hyperglycemia, cardiovascular diseases, and old age are important risk factors for severe outcomes of coronavirus infection, involving a hypercoagulable state. Early diagnosis and proper therapy in complicated SARS-CoV-2-infected cases could reduce mortality and the need for intensive care during hospitalization in patients with cardiometabolic comorbidities.

Clinical and biological heterogeneity of multisystem inflammatory syndrome in adults following SARS-CoV-2 infection: a case series

Importance

Multisystem inflammatory syndrome in adults (MIS-A) is a poorly understood complication of SARS-CoV-2 infection with significant morbidity and mortality.

Objective

Identify clinical, immunological, and histopathologic features of MIS-A to improve understanding of the pathophysiology and approach to treatment.

Design

Three cases of MIS-A following SARS-CoV-2 infection were clinically identified between October 2021 - March 2022 using the U.S. Centers for Disease Control and Prevention diagnostic criteria. Clinical, laboratory, imaging, and tissue data were assessed.

Findings

All three patients developed acute onset cardiogenic shock and demonstrated elevated inflammatory biomarkers at the time of hospital admission that resolved over time. One case co-occurred with new onset Type 1 diabetes and sepsis. Retrospective analysis of myocardial tissue from one case identified SARS-CoV-2 RNA. All three patients fully recovered with standard of care interventions plus immunomodulatory therapy that included intravenous immunoglobulin, corticosteroids, and in two cases, anakinra.

Conclusion

MIS-A is a severe post-acute sequela of COVID-19 characterized by systemic elevation of inflammatory biomarkers. In this series of three cases, we find that although clinical courses and co-existent diseases vary, even severe presentations have potential for full recovery with prompt recognition and treatment. In addition to cardiogenic shock, glucose intolerance, unmasking of autoimmune disease, and sepsis can be features of MIS-A, and SARS-CoV-2 myocarditis can lead to a similar clinical syndrome.

Post-authorization safety surveillance of Ad.26.COV2.S vaccine: Reports to the Vaccine Adverse Event Reporting System and v-safe, February 2021-February 2022

BACKGROUND

On 2/27/2021, FDA authorized Janssen COVID-19 Vaccine (Ad.26.COV2.S) for use in individuals 18 years of age and older. Vaccine safety was monitored using the Vaccine Adverse Event Reporting System (VAERS), a national passive surveillance system, and v-safe, a smartphone-based surveillance system.

METHODS

VAERS and v-safe data from 2/27/2021 to 2/28/2022 were analyzed. Descriptive analyses included sex, age, race/ethnicity, seriousness, AEs of special interest (AESIs), and cause of death. For prespecified AESIs, reporting rates were calculated using the total number of doses of Ad26.COV2.S administered. For myopericarditis, observed-to-expected (O/E) analysis was performed based on the number verified cases, vaccine administration data, and published background rates. Proportions of v-safe participants reporting local and systemic reactions, as well as health impacts, were calculated.

RESULTS

During the analytic period, 17,018,042 doses of Ad26.COV2.S were administered in the United States, and VAERS received 67,995 reports of AEs after Ad26.COV2.S vaccination. Most AEs (59,750; 87.9 %) were non-serious and were similar to those observed during clinical trials. Serious AEs included COVID-19 disease, coagulopathy (including thrombosis with thrombocytopenia syndrome; TTS), myocardial infarction, Bell's Palsy, and Guillain-Barré syndrome (GBS). Among AESIs, reporting rates per million doses of Ad26.COV2.S administered ranged from 0.06 for multisystem inflammatory syndrome in children to 263.43 for COVID-19 disease. O/E analysis revealed elevated reporting rate ratios (RRs) for myopericarditis; among adults ages 18-64 years, the RR was 3.19 (95 % CI 2.00, 4.83) within 7 days and 1.79 (95 % CI 1.26, 2.46) within 21 days of vaccination. Of 416,384 Ad26.COV2.S recipients enrolled into v-safe, 60.9 % reported local symptoms (e.g. injection site pain) and 75.9 % reported systemic symptoms (e.g., fatigue, headache). One-third of participants (141,334; 33.9 %) reported a health impact, but only 1.4 % sought medical care.

CONCLUSION

Our review confirmed previously established safety risks for TTS and GBS and identified a potential safety concern for myocarditis.

Biventricular Takotsubo Cardiomyopathy as an Unusual Presentation of SARS-CoV-2 mRNA Vaccine-Associated Multisystemic Inflammatory Syndrome

Biventricular takotsubo cardiomyopathy (BiTCM) is a rare entity, seldom reported. We describe a case of a female presenting with multisystemic inflammatory syndrome associated with the administration of a vaccine against coronavirus disease 2019 (COVID-19). In this particular case, the patient experienced the onset of symptoms shortly after receiving a COVID-19 vaccine. Early recognition of biventricular takotsubo cardiomyopathy and timely initiation of appropriate treatment are crucial. Prompt management includes stabilizing the patient's hemodynamic status, alleviating symptoms, and addressing any underlying causes, such as inflammation or immune-related responses. Close clinical surveillance is necessary to monitor the patient's cardiac function, assess response to treatment, and prevent potential complications.

Multisystem Inflammatory Syndrome: A Case in an Adult With Controlled Lymphoma and a Persistent SARS-CoV-2 Infection

Multisystem inflammatory syndrome (MIS) is a new and rare complication of COVID-19 that usually occurs in children. An increasing number of cases of MIS in adults are described in the literature. The condition is associated with high mortality, and treatment is non-standardized. Clinical pictures are heterogeneous, and diagnosis is very challenging. Here we describe a case of MIS in a 60-year-old man with previous follicular lymphoma treated with obinutuzumab and recent SARS-CoV-2 infections. He complained of an unknown fever and developed pancytopenia during the hospitalization, associated with a general clinical worsening. The patient was successfully treated with intravenous immunoglobulin and steroids.

A Young Adult With Multisystem Inflammatory Syndrome Following Weeks of Initial COVID-19 Respiratory Infection, With No Prior COVID-19 Vaccination: A Case Report

Multisystem inflammatory syndrome (MIS) following COVID-19, a condition primarily diagnosed in children, has also been observed less frequently in adults. It usually presents with a multitude of symptoms, mimicking a shock-like state characterized by multiple organ failure. Diagnosis often involves ruling out other conditions and timely management to mitigate morbidity and mortality. In this case, a 39-year-old unvaccinated Caucasian male patient reported symptoms of fever, chills, night sweats, diarrhea, headache, nasal congestion, and facial pain. Despite treatment with antipyretics, the fever persisted. The patient had tested positive for COVID-19 via polymerase chain reaction (PCR) six weeks prior. Clinical findings included low oxygen saturation, sinus tachycardia, abnormal liver function, elevated inflammatory markers, a negative respiratory viral panel, a negative immunologic workup, and a positive Clostridium difficile (C. difficile) PCR. Following complaints of chest pain which quickly escalated to cardiac arrest, he was diagnosed with myopericarditis. These manifestations met the multisystem inflammatory syndrome in adults (MIS-A) diagnostic criteria as stipulated by the Centers for Disease Control and Prevention. The diagnosis of MIS-A was reached through exclusion. Notably, the patient responded well to symptomatic management. Given the infrequent occurrence of MIS-A cases, even in 2023, it remains a challenging diagnosis. Despite existing guidelines for management, the recovery of this patient solely through symptomatic treatment prior to the consideration of conventional treatment is striking. The patient had concurrent infections, including a C. difficile infection, but these did not account for the overall clinical presentation, particularly the myopericarditis and positive laboratory findings.

First confirmed case of multisystem inflammatory syndrome in adult in Egypt

Key Clinical Message

Our case report demonstrates extremely uncommon data associated with MIS-A, such as cholestatic jaundice, anemia, and quickly progressing pneumonia. IVIG and pulse steroid medications are the best treatments for improving clinical outcomes.

Abstract

We report a case of multiple organ dysfunctions due to MIS-A in an adult with a history of suspected COVID-19. Our case demonstrates extremely uncommon data associated with MIS-A, such as cholestatic jaundice, anemia, and quickly progressing pneumonia. IVIG and pulse steroid medications are the best treatments for improving clinical outcomes.

Cardiac Involvement in Patients with Multisystem Inflammatory Syndrome in Children (MIS-C) in Poland

Multisystem inflammatory syndrome in children (MIS-C) is an immune-mediated complication of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Cardiovascular system is commonly involved. Acute heart failure (AHF) is the most severe complication of MIS-C, leading to cardiogenic shock. The aim of the study was to characterise the course of MIS-C with a focus on cardiovascular involvement, based on echocardiographic (echo) evaluation, in 498 children (median age 8.3 years, 63% boys) hospitalised in 50 cities in Poland. Among them, 456 (91.5%) had cardiovascular system involvement: 190 (48.2%) of patients had (most commonly atrioventricular) valvular insufficiency, 155 (41.0%) had contractility abnormalities and 132 (35.6%) had decreased left ventricular ejection fraction (LVEF < 55%). Most of these abnormalities improved within a few days. Analysis of the results obtained from two echo descriptions (a median of 5 days apart) revealed a >10% increase in LVEF even in children with primarily normal LVEF. Lower levels of lymphocytes, platelets and sodium and higher levels of inflammatory markers on admission were significantly more common among older children with contractility dysfunction, while younger children developed coronary artery abnormality (CAA) more often. The incidence of ventricular dysfunction might be underestimated. The majority of children with AHF improved significantly within a few days. CAAs were relatively rare. Children with impaired contractility as well as other cardiac abnormalities differed significantly from children without such conditions. Due to the exploratory nature of this study, these findings should be confirmed in further studies.

Human Amylin in the Presence of SARS-COV-2 Protein Fragments

COVID-19 can lead to the onset of type-II diabetes, which is associated with the aggregation of islet amyloid polypeptides, also called amylin. Using molecular dynamics simulations, we investigate how the equilibrium between amylin monomers in its functional form and fibrils associated with diabetes is altered in the presence of SARS-COV-2 protein fragments. For this purpose, we study the interaction between the fragment SFYVYSRVK of the envelope protein or the fragment FKNIDGYFKI of the spike protein with the monomer and two amylin fibril models. Our results are compared with earlier work studying such interactions for the two different proteins.

A Case of COVID-19-Induced Immune Thrombocytopenia (ITP) in an Adult Female: An Under-Recognized Emerging Phenomenon

Coronavirus disease 2019 (COVID-19) follows a mild course in majority of cases, but some patients may develop non-pulmonary yet life-threatening complications. A Pandora's box had been opened when multisystem hyper-inflammatory syndromes and autoimmune diseases that had been described previously in children and young adults, that are associated with COVID-19, have now emerged in adults. They need to be recognized as important sequelae of severe COVID-19 disease. Immune thrombocytopenia (ITP) or thrombocytopenic purpura is an autoantibody and T-cell-mediated autoimmune disorder characterized by isolated thrombocytopenia, which can be triggered by different infections. First-line treatment of severe ITP includes platelet transfusions in life-threatening cases, followed by corticosteroids and intravenous immunoglobulins (IVIG). Since the beginning of the pandemic, more and more cases of COVID-19-associated ITP have been reported. We report a case of acquired ITP in a young woman that could only be attributed to her COVID-19 infection and was refractory to platelet transfusion, requiring further treatments. The aim of this report is to review some of the etiologies and purposed molecular mechanisms of the autoimmune nature of the disease and to focus on diagnosis and treatment. We will review the current literature surrounding this non-pulmonary manifestation of COVID-19 and current treatment options for this uncommon presentation of ITP.

Severe COVID-19 versus multisystem inflammatory syndrome: comparing two critical outcomes of SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with diverse host response immunodynamics and variable inflammatory manifestations. Several immune-modulating risk factors can contribute to a more severe coronavirus disease 2019 (COVID-19) course with increased morbidity and mortality. The comparatively rare post-infectious multisystem inflammatory syndrome (MIS) can develop in formerly healthy individuals, with accelerated progression to life-threatening illness. A common trajectory of immune dysregulation forms a continuum of the COVID-19 spectrum and MIS; however, severity of COVID-19 or the development of MIS is dependent on distinct aetiological factors that produce variable host inflammatory responses to infection with different spatiotemporal manifestations, a comprehensive understanding of which is necessary to set better targeted therapeutic and preventative strategies for both.

Multisystem Inflammatory Syndrome Causing Mixed Cardiogenic Shock in a 34-Year-Old With Influenza A

Multisystem inflammatory syndrome in adults (MIS-A) is a sequela of COVID-19 and can cause mixed cardiogenic and vasodilatory shock. We present the case of a 34-year-old female who presented with mixed cardiogenic and vasodilatory shock and was found to be influenza A positive while also meeting criteria for MIS-A. She responded well to treatment with steroids and intravenous immunoglobulin (IVIG).

Proinflammatory Responses in SARS-CoV-2 and Soluble Spike Glycoprotein S1 Subunit Activated Human Macrophages

Critically ill COVID-19 patients display signs of generalized hyperinflammation. Macrophages trigger inflammation to eliminate pathogens and repair tissue, but this process can also lead to hyperinflammation and resulting exaggerated disease. The role of macrophages in dysregulated inflammation during SARS-CoV-2 infection is poorly understood. We inoculated and treated human macrophage cell line THP-1 with SARS-CoV-2 and purified, glycosylated, soluble SARS-CoV-2 spike protein S1 subunit (S1) to clarify the role of macrophages in pro-inflammatory responses. Soluble S1 upregulated TNF-α and CXCL10 mRNAs, and induced secretion of TNF-α from THP-1 macrophages. While THP-1 macrophages did not support productive SARS-CoV-2 replication or viral entry, virus exposure resulted in upregulation of both TNF-α and CXCL10 genes. Our study shows that extracellular soluble S1 protein is a key viral component inducing pro-inflammatory responses in macrophages, independent of virus replication. Thus, virus- or soluble S1-activated macrophages may become sources of pro-inflammatory mediators contributing to hyperinflammation in COVID-19 patients.

Multisystem inflammatory syndrome in neonates (MIS-N): a systematic review

Recently, a new pattern of multisystem inflammatory syndrome following an infection with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) has emerged globally. The initial cases were described in the adult population followed by sporadic cases in the pediatric population also. By the end of 2020, similar reports were recognised in the neonatal age group. The purpose of this study was to systematically review clinical characteristics, laboratory parameters, treatment, and outcomes of neonates with multisystem inflammatory syndrome in neonates (MIS-N). A systematic review was conducted after registering with PROSPERO and electronic databases including MEDLINE, EMBASE, PubMed, SCOPUS, Google Scholar, and Web of Science were searched from January 1st 2020 till September 30th 2022. A total of 27 studies describing 104 neonates were analysed. The mean gestation age and birth weight was 35.9 ± 3.3 weeks and 2255.7 ± 783.7 g respectively. A large proportion (91.3%) of the reported cases belonged to the South-East Asian region. The median age of presentation was 2 days (range: 1-28 days) with cardiovascular system being the predominant system involved in 83.65% followed by respiratory (64.42%). Fever was noted in only 20.2%. Commonly elevated inflammatory markers were IL-6 in 86.7% and D-dimer in 81.1%. Echocardiographic evaluation suggested ventricular dysfunction in 35.8% and dilated coronary arteries in 28.3%. Evidence of SARS-CoV-2 antibodies (IgG or IgM) was seen in 95.9% neonates and evidence of maternal SARS-CoV-2 infection, either as history of COVID infection or positive antigen or antibody test, was noted in 100% of the cases. Early MIS-N was reported in 58 (55.8%) cases, late MIS-N in 28 (26.9%), and 18 cases (17.3%) did not report the timing of presentation. There was a statistically increased proportion of preterm infants (67.2%, p < 0.001), and a trend towards increased low birth weight infants, in the early MIS-N group when compared to the infants with late MIS-N. Fever (39.3%), central nervous system (50%), and gastrointestinal manifestations (57.1%) were significantly higher in the late MIS-N group (p = 0.03, 0.02, 0.01 respectively). The anti-inflammatory agents used for the treatment of MIS-N included steroids 80.8% which were given for a median of 10 (range 3-35) days and IVIg in 79.2% with a median of 2 (range 1-5) doses. The outcomes were available for 98 cases, of whom 8 (8.2%) died during treatment in hospital and 90 (91.8%) were successfully discharged home.   Conclusion: MIS-N has a predilection for late preterm males with predominant cardiovascular involvement. The diagnosis is challenging in neonatal period due to overlap with neonatal morbidities and a high risk of suspicion is warranted, especially in presence of supportive maternal and neonatal clinical history. The major limitation of the review was inclusion of case reports and case series, and highlights need of global registries for MIS-N. What is Known: • A new pattern of multisystem inflammatory syndrome following SARS-CoV-2 infection has emerged in adult population with sporadic cases now being reported in neonates. What is New: • MIS-N is an emerging condition with a heterogeneous spectrum and has a predilection for late preterm male infants. Cardiovascular system is the predominant system involved  followed by respiratory, however fever remains an uncommon presentation unlike other age-groups. There are two subtypes based on timing of presentation, with early MIS-N being reported more in preterm and low-birth weight infants.

Understanding COVID-19 in children: immune determinants and post-infection conditions

Coronavirus disease 2019 in children presents with milder clinical manifestations than in adults. On the other hand, the presence of a wide range of inflammatory manifestations, including multisystem inflammatory syndrome in children (MIS-C), in the period after infection suggests a particular susceptibility of some children toward severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Both protective factors that prevent evolution to severe forms and risk factors for post-infectious conditions are likely to be found in age-related differences in the immune system. The prompt innate response with type I IFN production and the generation of neutralizing antibodies play a crucial role in containing the infection. The greater number of naive and regulatory cells in children helps to avoid the cytokine storm while the causes of the intense inflammatory response in MIS-C need to be elucidated. This review aims to analyze the main results of the recent literature assessing immune response to SARS-CoV-2 over the pediatric age group. We summarized such observations by dividing them into innate and acquired immunity, then reporting how altered immune responses can determine post-infectious conditions. IMPACT: The main immune markers of acute SARS-CoV-2 infection in children are summarized in this review. This paper reports a broad overview of age-related differences in the immune response to SARS-CoV-2 and emerging post-infection conditions. A summary of currently available therapies for the pediatric age group is provided.

How Does COVID-19 Affect the Heart?

PURPOSE OF REVIEW

Cardiac consequences occur in both acute COVID-19 and post-acute sequelae of COVID-19 (PASC). Here, we highlight the current understanding about COVID-19 cardiac effects, based upon clinical, imaging, autopsy, and molecular studies.

RECENT FINDINGS

COVID-19 cardiac effects are heterogeneous. Multiple, concurrent cardiac histopathologic findings have been detected on autopsies of COVID-19 non-survivors. Microthrombi and cardiomyocyte necrosis are commonly detected. Macrophages often infiltrate the heart at high density but without fulfilling histologic criteria for myocarditis. The high prevalences of microthrombi and inflammatory infiltrates in fatal COVID-19 raise the concern that recovered COVID-19 patients may have similar but subclinical cardiac pathology. Molecular studies suggest that SARS-CoV-2 infection of cardiac pericytes, dysregulated immunothrombosis, and pro-inflammatory and anti-fibrinolytic responses underlie COVID-19 cardiac pathology. The extent and nature by which mild COVID-19 affects the heart is unknown. Imaging and epidemiologic studies of recovered COVID-19 patients suggest that even mild illness confers increased risks of cardiac inflammation, cardiovascular disorders, and cardiovascular death. The mechanistic details of COVID-19 cardiac pathophysiology remain under active investigation. The ongoing evolution of SARS-CoV-2 variants and vast numbers of recovered COVID-19 patients portend a burgeoning global cardiovascular disease burden. Our ability to prevent and treat cardiovascular disease in the future will likely depend on comprehensive understanding of COVID-19 cardiac pathophysiologic phenotypes.

Multisystem Inflammatory Syndrome

The novel coronavirus (severe acute respiratory syndrome coronavirus-2), also referred to as coronavirus disease 2019, has caused a global pandemic that cost more than 900,000 deaths and affected nearly 80 million Americans since the start of the pandemic in early 2020. A majority of cases have primarily been reported in the adult population. Initially, lower morbidity and mortality rates were noted in children, compared with adults. However, some pediatric patients have been shown to develop a rare, but severe complication of severe acute respiratory syndrome coronavirus-2 infection, referred to as Multisystem Inflammatory Syndrome in Children. The condition has now been reported in adults as well. In this article, the origins, clinical features, pathogenesis, treatment, and latest literature on multisystem inflammatory syndrome are explored.

Fatal multisystem inflammatory syndrome in a 78-year-old adult after severe COVID-19 pneumonia during 2022 Omicron variant epidemic in Shanghai, China

Multisystem inflammatory syndrome adult type (MIS-A) is a rare type of post-acute COVID-19 syndrome which more frequently occurred in younger population. Here we present a 78-year-old Chinese female, the oldest case reported, diagnosed with MIS-A who had severe SARS-CoV-2 infection. She was diagnosed with severe COVID-19 and experienced an unexpected sudden hemodynamic collapse in the recovery period within three weeks. Her platelet count was sharply dropped, accompanied with sustained cardiac, kidney and liver injury. She was diagnosed with MIS-A according to criteria established by Center of Disease Control and Prevention. Though her condition was improved under administrating with high dose of methylprednisolone and intravenous immunoglobulin, methylprednisolone was unable to withdraw till two weeks as her partial pressure of oxygen/fraction of inspiration oxygen ratio and platelet count dropped on the heels of decreasing dosage. Unfortunately, the patient's condition gradually deteriorated with the development of severe nosocomial pneumonia. We presented this rare case in order to emphasize that MIS-A could occur in the elderly and the management of this population might be more difficult as the condition of the elderly with SARS-CoV-2 infection and MIS-A might be more severe.

Multisystem Inflammatory Syndrome in Children

Multisystem inflammatory disease in children (MIS-C) is a condition typically seen 3 to 6 weeks after acute infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Believed to be a postinfection hyperinflammatory response, the clinical manifestation of this viral sequelae can vary significantly in severity and symptomatic presentation. Clinical prodrome includes persistent fever and dysfunction of at least two organ systems. Often developing after asymptomatic or mildly symptomatic coronavirus disease 2019 (COVID-19) infection, MIS-C is a diagnosis of exclusion that requires evaluation for other infectious or noninfectious etiology for symptoms. Vital sign instability, including fever, tachycardia, and hypotension; laboratory studies demonstrating elevated inflammatory markers and elevated cardiac markers; and positive SARS-CoV-2 polymerase chain reaction, SARS-CoV-2 antibodies, or exposure to someone with confirmed COVID-19 infection 4 to 6 weeks before clinical presentation are used to diagnose this condition. Skin and mucosal involvement, gastrointestinal symptoms, and neurologic manifestations are also commonly seen. An echocardiogram is indicated to evaluate for cardiac dysfunction, including but not limited to coronary artery enlargement, left ventricular dysfunction, arrythmias, or atrioventricular block. [Pediatr Ann. 2023;52(3):e114-e121.].

Multisystem Inflammatory Syndrome in Adults Associated With COVID-19: A Case Series on the Importance of Early Diagnosis and Corticosteroid Therapy in Prognosis

Multisystem inflammatory syndrome in adults (MIS-A) is a rare condition that can occur after an adult has been infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). It can occur anywhere between two and 12 weeks after the beginning of acute coronavirus disease 2019 (COVID-19) infection and is characterized by extrapulmonary multiorgan failure. It is primarily seen in young and previously healthy individuals. The exact prevalence of MIS-A is unclear. It is likely underdiagnosed due to overlapping symptoms with severe COVID-19 and difficulty in identifying the syndrome without a preceding COVID-19 infection. The pathogenesis of MIS-A is also largely unknown but is likely caused by an immune response that is dysregulated or antibody-mediated. Treatment primarily involves corticosteroids, but severe cases may require intravenous immune globulin (IVIG). The timing of starting corticosteroid therapy is crucial, as delays can result in increased complications and a longer hospital stay.

Acute Myocarditis and Pericarditis After m-RNA COVID-19 Vaccinations-A Single-Centre Retrospective Analysis

BACKGROUND

With the rapid rollout of COVID-19 vaccinations, numerous associated and suspected adverse events have been reported nationally and worldwide. Literature reporting confirmed cases of pericarditis and myocarditis following SARS-CoV-2 mRNA vaccinations has evolved, with a predominance in adolescent males following the second dose.

METHODS

This was a retrospective analysis of all patients presenting to St Vincent's Hospital, Sydney, Australia with suspected COVID-19 vaccine-related myocarditis and pericarditis. The Brighton Collaboration Case Definitions of Myocarditis and Pericarditis were used to categorise patients into groups based on diagnostic certainty. Cardiac magnetic resonance imaging findings were reviewed against updated Lake Louise Criteria for diagnosing patients with suspected myocarditis.

RESULTS

We report 10 cases of confirmed, possible or probable myocarditis and pericarditis. The mean age of presentation in the vaccine group was 33±9.0 years. The most common presenting symptom was pleuritic chest pain (n=8, 80%). Eight patients (80%) had electrocardiogram (ECG) abnormalities (n=6 pericarditis, n=2 myocarditis). Five patients (50%) had a minimum 24 hours of cardiac monitoring. One patient had multisystem inflammatory syndrome following vaccination (MIS-V) with severely impaired left ventricular ejection fraction and required admission to the intensive care unit.

DISCUSSION AND CONCLUSION

Cardiac complications post mRNA vaccines are rare. Our case series reflects the worldwide data that vaccine-related myocarditis and pericarditis most frequently occur in young males, following the second dose of the vaccine. These cardiac side effects are mild and self-limiting, with adequate responses to oral anti-inflammatories. One patient developed a severe reaction, with no fatal cases.

Immune and coagulation profiles in 3 adults with multisystem inflammatory syndrome

Introduction: There is a paucity of information on the cytokine, complement, endothelial activation, and coagulation profiles of multisystem inflammatory syndrome in adults (MIS-A), a rare but serious complication following recovery from SARS-CoV-2 infection. We aim to examine the immune biomarker and coagulation profiles in association with the clinical presentation and course of MIS-A. Method: The clinical features of MIS-A patients admitted to our tertiary hospital were documented. Their levels of interleukin (IL)-1β, IL-6, IL-10, IL-17, IL-18, interferon-α (IFN-α), IFN-γ, interferon gamma-induced protein 10 (IP-10), tumour necrosis factor (TNF)-α, monocyte chemoattractant protein (MCP)-1, complement activation product (complement 5a [C5a]), and endothelial biomarker intercellular adhesion molecule-1 (ICAM-1) levels were assayed. The haemostatic profile was assessed with standard coagulation testing and thromboelastography. Results: Three male patients were diagnosed with MIS-A at our centre from January to June 2022 with a median age of 55 years. All had tested positive for SARS-CoV-2 12–62 days prior to MIS-A presentation, with gastrointestinal and cardiovascular systems as the most commonly involved. Levels of IL-6, IL-10, IL-18, IP-10 and MCP-1 were raised whereas IL-1β, IFN-α, IFN-γ, IL-17 and TNF-α remained normal. Markedly elevated levels of C-reactive protein (CRP), ferritin and ICAM-1 were present in all. C5a was elevated in 2 patients. A hypercoagulable state was demonstrated by raised levels of D-dimer, factor VIII, von Willebrand factor antigen, and ristocetin cofactor with corresponding raised parameters in thromboelastography in the 2 patients who had their coagulation profile assessed. Conclusion: MIS-A patients demonstrate activation of pro-inflammatory cytokines, endotheliopathy, complement hyperactivation and hypercoagulability. Keywords: COVID-19, cytokines, hypercoagulability, hyperinflammatory syndrome

A Young Adult With Multisystem Inflammatory Syndrome in Adults With Concomitant Mycoplasma Infection: A Case Report

Several cases of Multisystem Inflammatory Syndrome in Adults (MIS-A) have been reported in adults since June 2020 after COVID-19 was first reported in December 2019. It was initially reported in children as MIS-C with Kawasaki-like disease, but a similar condition has been well recognized in adults. Although Mycoplasma co-infection has been reported with COVID-19, to our knowledge, concomitant Mycoplasma pneumoniae infection has not been reported together with MIS-A. We present a case of MIS-A with concomitant M. pneumoniae infection. It is unclear if concomitant Mycoplasma infection resulted in increased severity of the patient's illness or if it resulted in inciting the immune response in our patient who had recently recovered from COVID-19 infection. This case highlights the need to diagnose a patient with a typical presentation of MIS-A and any concomitant infection or illnesses.

Inborn errors of OAS-RNase L in SARS-CoV-2-related multisystem inflammatory syndrome in children

Multisystem inflammatory syndrome in children (MIS-C) is a rare and severe condition that follows benign COVID-19. We report autosomal recessive deficiencies of OAS1, OAS2, or RNASEL in five unrelated children with MIS-C. The cytosolic double-stranded RNA (dsRNA)-sensing OAS1 and OAS2 generate 2'-5'-linked oligoadenylates (2-5A) that activate the single-stranded RNA-degrading ribonuclease L (RNase L). Monocytic cell lines and primary myeloid cells with OAS1, OAS2, or RNase L deficiencies produce excessive amounts of inflammatory cytokines upon dsRNA or severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) stimulation. Exogenous 2-5A suppresses cytokine production in OAS1-deficient but not RNase L-deficient cells. Cytokine production in RNase L-deficient cells is impaired by MDA5 or RIG-I deficiency and abolished by mitochondrial antiviral-signaling protein (MAVS) deficiency. Recessive OAS-RNase L deficiencies in these patients unleash the production of SARS-CoV-2-triggered, MAVS-mediated inflammatory cytokines by mononuclear phagocytes, thereby underlying MIS-C.